Previously, some people online believe that the suspects have already been identified and that one of them is a Brown University student named Sunil Tripathi, who has been missing since March.

NBC's sources have specifically denied this. And based on what we know right now, it seems highly unlikely that Tripathi is involved.

The theory that Tripathi might have been involved in the bombing first surfaced on social media a couple of days ago. This theory gained steam last night when people reported hearing his name and another name on a Boston police scanner.

Most online references to the name on the scanner appear to tie back to this tweet from a Twitter user describing himself as cameraman at Eyewitness News in Hartford. Many people have also circulated photos that showed some resemblance in some photos between Tripathi and the Boston bombing suspect 2.

There is much less of a resemblance in the latest photo released by the FBI (excerpt above). And no one has been able to point us to an exact transcription of what was reportedly said on the Boston police scanner last night, or provided any context in which the names might have been mentioned.